Hamadryas

The habitats where hamadryas baboons live make them vulnerable to various apex predators, such as lions and spotted hyenas. Other predators include snakes and birds of prey (Schreier and Swedell, 2012). As for geladas, their predators comprise of wild dogs, jackals, leopards, foxes and hyenas (Dunbar, 1975). However, the highly structured group configuration of hamadryas and geladas make it difficult for predators to attack due to signaling capabilities, which warns the members ahead of time. Furthermore, for hamadryas baboons the congregation of multiple male leaders in a band increases the rate of success in fending off attacks (Kummer, 1968, Nowak, 1999; Stammbach, 1987).
Ecological Causes of Differences and Similarities
Hamadryas and geladas
are closely related in terms of phylogeny. They share many similarities from being a part of the same subfamily of primates. Yet, ecology also plays an influential role in the physical traits and behaviors of these two species. Many characteristics have been retained, but also many divergent qualities are seen throughout the two species of baboons, such as habitat preference, social organization, etc.
An important factor to consider is their habitat. Though both species live in the same country, they inhabit different environments. This causes distinct traits of morphology and dietary preference to develop. Over time, their ancestors have established adaptations to thrive in their environment. Hamadryas baboons live in sub desert environment with patchy resources (Schreier and Swedell, 2012).
This surrounding presents feeding challenges because not too many organisms can live under these conditions. In order to increase their chances of survival, they have adapted in eating a multitude of different sustenance. This shows a direct effect in how ecology plays a role in their feeding behavior.
The environment also influences feeding behavior of geladas. Rather than multiple options, geladas are specialized graminivorous feeders because of their high grassland habitats. This feeding preference allows them to exploit their surrounding. In conclusion, different habitats lead to different feeding behaviors that allow them to take full advantage of the resources.
One of the unique characteristics between hamadryas and geladas is found within their social organization. Hamadryas male leaders exhibit aggressive behavior and use force to condition females to stay in close proximity. This social behavior deviates from other cercopithecines (Kummer, 1968). A possible reason for this deviation is due to their predators. Males who condition females to stay close in proximity have a higher chance of protecting the female from predation. Consequently, their environment presents a high vulnerability rate from their predators because of the lack of tree coverage. Therefore, following the male leaders command increases the chances of survival. Furthermore, male leaders are the only
members to engage in combat. Hence, the aggressive behavior benefits most members of the OMU
As for geladas, males are not the dominant sex and exhibit no aggressive behavior towards the females. A reason for this can also be traced back to their environment and predation risk. Since geladas live in high grasslands where there is sufficient coverage from predators, especially birds of prey, having an aggressive male leader who conditions females to stay in close proximity is less important. Furthermore, geladas are not territorial primates; therefore aggression of a single male is not necessary to protect resources.
Furthermore, the social structure of both species involves a multi level organization.
The significance of multi level organization is different for both species. Geladas are free to leave the band and associate themselves with other non-related OMUs. The possible explanation for this is food availability in their habitat. Geladas are surrounded with their food resources. On the contrary, hamadryas baboons follow a strict and complex social organization. Males and females are restricted within their bands. Since they live in habitats with rare resources like water holes and rocky cliffs, there is a high competition against other bands. Therefore, access to essential resources depends on maintaining a large stable group. This exemplifies the significant relationship between social organization and habitat.
Ultimately, further research needs to be done to support ecological correlation with the differentiation of closely related species. However, the divergent qualities of both geladas and hamadryas are influenced greatly by their environment. These characteristics allow them to be adaptable primates and thrive with the given
circumstances.